Samsung LN48C630K1F no video.

[jet]

Hi All,

I have a Samsung LN48C630K1F LCD TV with no video. When the unit is plugged in the AC (120 VAC North America) the red power LED blinks 5 time and the Samsung tune is heard from the speaker and the red LED is off. If I use the remote to turn on the unit on the red LED comes on solid and another Samsung tune is heard, if I then switch it off and the led is off and the Samsung tune is heard again.

I remove the back and there are no apparent bad cap. I measured the voltage at CN1802 (PSU) and I get the following DC voltages in

Standby mode from right to left (see pic 2506)

pin 1-2 = 8.89
pin 3-6 = 0
pin 7 = 12.17

in on mode

all pins 0 V

The boards are PSU BN44-00341B and video BN41-01563A. I have attached pics. I will check back from work tomorrow.

Thanks from Canada

[budm]

Re: Samsung LN48C630K1F no video.

Can we see the whole back side of the TV so we can see how all the boards are connected together?

[budm]

Re: Samsung LN48C630K1F no video.

Can I get good close up pictures of the white rectangular cap CI818 sitting next the white fuse and the heatsink in the middle of the board? It has 2W 474K printed on top, look to see if it has any bulge on the sides.
Samsung BN44-00341B Power Supply / Backlight Inverter
http://www.shopjimmy.com/samsung-bn4...t-inverter.htm

Pictures provided by shopjimmy.

[jet]

Re: Samsung LN48C630K1F no video.

Trying to upload picture but the site keeps timing out on me so I will try less pics at a time. BTW those caps do not look bulged. I will remove them from the PCB tomorrow and test them with cap meter.

[jet]

Re: Samsung LN48C630K1F no video.

one more try tonight for pic upload

no luck will try in morning:


ERROR 500 - Internal Server Error!
The following error occurred:

The requested URL caused an internal server error.

If you get this message repeatedly please contact the webmaster.

[budm]

Re: Samsung LN48C630K1F no video.

The site was going on line off line for last 10 minutes for me, it is getting worst.

[jet]

Re: Samsung LN48C630K1F no video.

well one when up they might be to big

[jet]

Re: Samsung LN48C630K1F no video.

What is the value of that cap?

Edit: I removed cap and on close inspection it is bulged, als the measured value is very low nF range.

Can I get good close up pictures of the white rectangular cap CI818 sitting next the white fuse and the heatsink in the middle of the board? It has 2W 474K printed on top, look to see if it has any bulge on the sides.
Samsung BN44-00341B Power Supply / Backlight Inverter
http://www.shopjimmy.com/samsung-bn4...t-inverter.htm

Pictures provided by shopjimmy.

[budm]

Re: Samsung LN48C630K1F no video.

0.47uF 450V Polypropylene high frequency pulse type.
It is very commonly failed cap. I would go with 630V one.
450V:
http://www.digikey.com/product-searc...=ECW-F2W474JAQ
630V:
http://www.digikey.com/product-searc...rds=PCF1574-ND

[jet]

Re: Samsung LN48C630K1F no video.

Yes I just did some googling to figure out what the value is... At first I came up with 470uF because I thought that is what the K after the numbers meant, then the next hit explained the K as tolerance (10%). So yes the value is .47uF. How do we know the voltage and duty?

Thanks for the exact info budm. I have used a magnifying glass to inspect the other square caps and all look good, should I inspect any other circuitry?

Good call budm thanks again. BTW I will go with the 630V. Once it's up and running I will mark the thread solved

0.47uF 450V Polypropylene high frequency pulse type.
It is very commonly failed cap. I would go with 630V one.
450V:
http://www.digikey.com/product-searc...=ECW-F2W474JAQ
630V:
http://www.digikey.com/product-searc...rds=PCF1574-ND

[jet]

Re: Samsung LN48C630K1F no video.

I never did answer this thread, it was in fact the cap. TV work in now with 630V cap.